If guns were made illegal in the US (note: this doesn't mean that there are no guns, just that they are illegal, except for police and military), do you believe that the number of deaths due to assault (that is, not due to suicide or accidents) will increase, decrease, or stay roughly the same?

Please write "Increase", "Decrease", or "Same" in the subject line of your reply, and feel free to elaborate in the body of the reply.

The USA is populated with people that are much the same as those in comparable countries. In those countries, less guns available leads to less murders.

Bonus question:

What about injuries (cuts, broken bones, etc.)?

Also decreased.

The amount of violence in a society is not determined by a single-factor, however the thinking that gun violence is a viable 'last resort' will push some people to be more aggressive given this level of 'protection'. You may be less inclined to go too far in an altercation with a person that clearly outmatched you physically, but a gun 'levels the playing field'.

This also means that even those people relatively immune from unarmed or lesser-armed violence directed at them -- due to individual physical capacity or being in a larger group -- are still at risk from guns; hence they require a gun also for 'protection'.

The argument that more firearms leads to more personal safety is like arguing that if everyone walked around carrying a sword we'd all feel more secure from being attacked and potentially killed -- e.g. by swords.